Ionization explosion

Photoionization, where electrons are released by molecules following the absorption of energy from photons, has long been viewed as a non-radioactive means to ionize explosives in the vapor phase [39]. In recent years, two teams have sought to employ laser ionization with IMS for explosive determinations. A team at Implant Sciences Corporation has utilized a laser (or flash lamp) for sampling surfaces and for ionization of sample vapors in an IMS analyzer [40, 41]. In their approach, the sample is removed from a surface with an increased temperature from laser exposure. Gases (and presumably particulate matter) from over the surface are drawn into an IMS drift tube using a wall-free inlet vida supra). In the IMS drift tube, resonance multi-photon ionization by a laser is used to produce ions from the explosives. Their... 

Negative ionization methods preferentially ionize explosives (O), but can t avoid all background molecules ( )... 

APCI is a well-known technique for ionizing explosive molecules. A high voltage of about -2 kV is applied to a needle electrode to produce a negative corona discharge. The typical ionization process of the explosive molecules (M) consists of two steps ... 

The behavior of curve 3 of Fig. 21, in the intermediate range where pAobs decreases with increasing pH, will lead to a phenomenon which may be referred to as an ionization explosion. This would manifest itself as an abnormal steepening of a titration curve in the region in which the... 

Copolymerization is effected by suspension or emulsion techniques under such conditions that tetrafluoroethylene, but not ethylene, may homopolymerize. Bulk polymerization is not commercially feasible, because of heat-transfer limitations and explosion hazard of the comonomer mixture. Polymerizations typically take place below 100°C and 5 MPa (50 atm). Initiators include peroxides, redox systems (10), free-radical sources (11), and ionizing radiation (12). 

The effects of ionizing radiation on expls and related energetic materials have been well investigated over the years (see Radiation Effects on Explosives in Vol 9) and are quite predictable. 

The total energy, the structure, and the ionization pattern of the more stable phenyl derivative have been calculated.52,33 The controlled explosion of triazide(phenyl)silane in a flash-pyrolysis apparatus under approximately unimolecular conditions (p = 10-3 Pa, c = 10 2 3 mil/) can be carried out without danger.52,53... 

Most nitrile oxides are unstable, some of them are explosive. This fact hinders the study of their physical properties. Nevertheless, there are a number of publications concerning not only stable but also unstable nitrile oxides. In particular, mass spectral data for nitrile oxides among other unstable compounds containing an N+-X bond are summarized in a review (9). In such studies, the molecular ions must be generated using indirect procedures, including dissociative electron ionization, online flash-vacuum pyrolysis mass spectrometry, or ion-molecular reactions. Their characterization is mainly based on collisional activation and ion-molecular reactions. 

The use of radioactive ionization sources in areas subject to explosion or fire is undesirable because of the potential for area contamination with radioactive material which could be disseminated in the event of an explosion or fire. With proper precautions, however, electrical ionizing systems can be safely and effectively utilized while processing electrostatically sensitive energetic materials. Ions are generated electrically by corona discharge... 

Z. Takats, I. Cotte-Rodrfguez, N. Talaty, H. Chen, and R. G. Cooks. Direct, Trace Level Detection of Explosives on Ambient Surfaces by Desorption Electrospray Ionization Mass Spectrometry. Chem. Commun., no. 15 (2005) 1950-1952. 

Predictions of high explosive detonation based on the new approach yield excellent results. A similar theory for ionic species model43 compares very well with MD simulations. Nevertheless, high explosive chemical equilibrium calculations that include ionization are beyond the current abilities of the Cheetah code, because of the presence of multiple minima in the free energy surface. Such calculations will require additional algorithmic developments. In addition, the possibility of partial ionization, suggested by first principles simulations of water discussed below, also needs to be added to the Cheetah code framework. 

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